With the development of communication technologies, more and more people use terminals for communications. To extend social circles, terminal users will frequently recommend each other. For example, a user B recommends the contact information of a user C to a user A. When the user C receives a call from the user A, since the user C does not know in advance that the telephone number of itself is recommended by the user B, and the user C does not store the contact information of the user A; therefore, the user C will consider the call from the user A as an unknown call. Consequently, estrangement may exist during the communication between the user C and the user of the unknown call.